1. Field of the Invention
The present invention relates to a probe card used for testing semiconductor products, such as ICs and LSIs.
2. Description of the Prior Art
In the manufacture of IC and LSI products in which a number of wafer chips are fixed on a base plate, the chips are individually tested prior to cutting them. For such testing a testing device, commonly called a prober, is employed, to which a probe card is connected. The testing is effected by connecting the probe pins or needles of the card to the electrodes on the semiconductor chips.
The probe cards at the earlier stage were adapted for use in testing integrated circuits having a relative low degree of integration, or LSIs having a relatively small number of testing terminals, and accordingly, it was sufficient that the probe cards had 48 probe needles around a chip of 2 centimeters in diameter. Such a probe card is disclosed in U.S. Pat. No. 3,835,381. However, as the integrated circuits are improved to intensify their degree of integration, it is become necessary to increase the number of probe needles. Recently there has arisen a demand in the industry for fixing 300 or more probe needles in the area of 8.times.8 mm. In line with this industrial trend, the number of testing electrodes on a semiconductor wafer chip has become so vast that they cannot be arranged at the peripheral portion alone of the chip as under the conventional practice, and it has become necessary to fill the whole area of the chip with electrodes, regularly or irregularly.
The present invention is directed toward meeting such demand in the industry, and has for its object to provide an improved probe card for testing wafer chips for use in IC and LSI products, wherein the probe card is provided with densely arranged probe needles.
A further object of the present invention is to provide an improved probe card capable of testing a wafer chip filled with electrodes.
Other objects and advantages of the present invention will become apparent from the detailed description given hereinafter; it should be understood, however, that the detailed description and specific embodiments are given by way of illustration only, since various changes and modifications with the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.